Darkhan

— In the towns that lay next on our itinerary, the Soviet-Mongolian partnership was much in evidence. In Darkhan, for example, founded just 20 years ago on the open grasslands, we saw the factories that provide 15 percent of Mongolia's total G.N.P.; they had been built by Russians and East Europeans. At the city hall, Mayor Tumurkhoyag told us proudly that his town was an example to all developing countries. Not the least among the achievements he cited was the development of two of Mongolia's five world champions in free-style wrestling, which, along with horsemanship and archery, is a national sport. Yet about half of Darkhan's population of 60,000 live in small wooden houses and yurts that are heated by wood and coal, with outside toilets.